Openapi documentation

[folland87]

BUG 1
Describe the bug
Last crawl model is not properly documented in /websites response

To Reproduce
Steps to reproduce the behavior:

1. Go to /docs
2. Click on GET /websites
3. See the model of last_crawl

Expected behavior
last_crawl should be documented as a Crawl model

BUG 2
Describe the bug
in CrawlModel field config.metadata_config is not properly documented.

To Reproduce
Steps to reproduce the behavior:

1. Go to /docs
2. Click on GET /api/websites/{website_id}/crawls
3. See the model of config.metadata_config

Expected behavior
should document all fields accessibility, responsiveness, good_practices, technologies_and_trackers, carbon_footprint

BUG 3
Describe the bug
Title and description are not correct

Expected behavior
The title and description should be meaningful.